docs: def elemd(item, inset):
      """
      Determine whether an item is an element of a double precision set.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/elemd_c.html
  
      :param item: Item to be tested.
      :type item: float
      :param inset: Set to be tested.
      :type inset: spiceypy.utils.support_types.SpiceCell
      :return: True if item is an element of set.
      :rtype: bool
      """
      assert isinstance(inset, stypes.SpiceCell)
      assert inset.dtype == 1
      item = ctypes.c_double(item)
      return bool(libspice.elemd_c(item, ctypes.byref(inset)))